The present invention relates to an image data storage method wherein an image is read from a silver halide film in which an image is captured through exposure and is converted into image data to be stored, and to an image processing method wherein image processing can be conducted on images in accordance with a date of photographing.
In addition to a conventional service to make a print from an image in a silver halide negative film that is brought in by a customer, there has been devised, in the field of photofinishing laboratories, a new service wherein various facilities such as a scanner, a printer and a server computer having large capacity (hereinafter referred to as an image server) are installed, and photographs obtained through photographing by a customer are converted into image data and then are stored in a storage medium such as CD and DVD, or images are printed to be offered. The image data of this type can be preserved as an electronic album that is original and peculiar to each customer.
Incidentally, the image data have an advantage that image reproduction can be carried out while keeping the initial image quality. However, there is a problem that it takes much time to read out specific data when a file name is unknown, because image data themselves are invisible.
For the situation stated above, there has been devised a retrieval method wherein, when educing specific image data from a vast amount of image data, retrieval is conducted based on the content feature such as information about a date stored corresponding to the image data mentioned above. The retrieval method of this kind makes it possible to detect specific image data efficiently, even when the file name of the image data is unknown.
However, one of the problems in practice of the retrieval method is who inputs content feature correlated with image data and which step the content feature are inputted. For example, since data such as a date of photographing and others are recorded simultaneously with photographing of a subject in the case of a digital still camera, these data can be used as content feature.
In a camera of a silver halide type, however, information such as a date or the like cannot be recorded in the case of the so-called 135 type camera which is firmly popular, although information of a date or the like can be recorded as magnetic information on a part of a silver halide negative film in the case of a camera that complies with an APS film. Therefore, when digitizing images in a negative film captured through exposure by a 135 type camera, an operator needs to input information of a date each time by correlating it with image data, which is time-consuming. In addition, when there is an inputting error, the image data are buried in a vast amount of image data, resulting in a fear that the image data are not found out again.
Further, since an image is formed through chemical reactions in the case of a silver halide film, there is a potential of deterioration of image quality such as color fading to a certain extent, if the image is preserved for a long time. If the image in a silver halide film preserved for a long time is digitized as it is, image data are preserved under the state of deteriorated image quality, which is not preferable. Though image data can be subjected to correction processing, on the other hand, a ground based on which the correction is conducted is unclear. Namely, correction processing cannot be conducted unless the extent of a change in image color is grasped.
On the other hand, among some photograph lovers, color-faded photographs are sometimes loved. For example, when silver halide photographs are preserved for a long time, colors of images are totally changed to sepia color, and this sepia color gives a rise to a nostalgic atmosphere of a peculiar sort. However, image data are hardly changed in terms of quality even when they are preserved for a long time and therefore, their image quality is kept to the initial state. Therefore, it is considered that images need to be faded in color naturally, like silver halide photographs.
An object of the invention is to provide an image data preservation method wherein date information correlated to image data can be inputted, and an image processing method wherein color fading of a silver halide film can be corrected, and images formed from image data can be subjected to effect processing which is natural and similar to silver halide photographs.
First structure: An image data preservation method wherein, when converting images in which date information is photographed into image data, information about the date is read and preserved to be correlated with the image data, as additional information.
Second structure: An image processing method wherein images on silver halide films or images on silver halide photographs in which a date is photographed are converted into image data, the date is read, and the image data are subjected to image processing to be correlated with the date.
Third structure: An image processing method wherein, when image data are inputted from an electronic image recording apparatus, information about the date added to the image data is read, and the image data are subjected to image processing to be correlated with the date.
In the image data preservation method of the First structure wherein, when converting images in which date information is photographed into image data, information about the date is read and preserved to be correlated with the image data, as additional information, an operator does not need to spend time to input date information each time and an inputting error can be prevented. Incidentally, for converting an image formed through photographing as a date into characters or numerical data, an OCR (optical character reading) function, for example, can be used. The OCR function will not be described in detail here because it is well-known.
Further, it is preferable that information about the date is used as a date of preparation (for example, a date of photographing) of the image data when detecting the image data, because it is less likely that the order of dates is reversed when images are arranged in the order of photographing.
If information about the date is housed in a header of a file containing the image data, retrieval turns out to be easy, which is preferable.
Incidentally, with regard to the image in which information about the date is photographed, images recorded in a silver halide film in which a date is photographed by the use of a date function of a camera, or silver halide photographs are given as an example. However, the invention is not limited to the foregoing, and X-ray images, for example, are also included in the invention.
In this case, when the same silver halide film includes, mixedly, an image wherein a date is not photographed or an image wherein a date is hardly recognized, and an image wherein a date is photographed, the date of the image wherein the date is photographed can be preserved as additional information for the image data corresponding to the image wherein a date is not photographed or the image wherein a date is hardly recognized.
Further, when images in each of which a date is photographed are present before and after an image wherein a date is not photographed or before and after an image wherein a date is hardly recognized, and when the dates are the same in the same silver halide film, the date of the image wherein the date is photographed can be preserved as additional information for the image data corresponding to the image wherein a date is not photographed or the image wherein a date is hardly recognized.
Further, when images in each of which a date is photographed are present before and after an image wherein a date is not photographed or before and after an image wherein a date is hardly recognized, and when the dates are different each other in the same silver halide film, the date or the period of time between the dates for the images in each of which the date is photographed can be preserved as additional information for the image data corresponding to the image wherein a date is not photographed or the image wherein a date is hardly recognized.
Further, when an image in which a date is photographed is present before an image wherein a date is not photographed or an image wherein a date is hardly recognized in the same silver halide film, the date after the date of the image wherein the date is photographed can be preserved as additional information for the image data corresponding to the image wherein a date is not photographed or the image wherein a date is hardly recognized.
Further, when an image in which a date is photographed is present after an image wherein a date is not photographed or an image wherein a date is hardly recognized in the same silver halide film, the date before the date of the image wherein the date is photographed can be preserved as additional information for the image data corresponding to the image wherein a date is not photographed or the image wherein a date is hardly recognized.
Further, when images in each of which a date is not photographed or images in each of which a date is hardly recognized only are present in the same silver halide film, a date of photographing or a period of time is presumed based on symbols or marks described on a cartridge of the silver halide film, and the presumed date of photographing can be preserved as additional information for the image data corresponding to the image wherein a date is not photographed or the image wherein a date is hardly recognized.
Further, when there is present an image wherein a date photographed therein is hardly recognized in the same silver halide film, the date photographed is educed by processing the above-mentioned image and an image photographed before or after the image, and the educed date can be preserved as additional information, for image data corresponding to the image wherein the date photographed therein is hardly recognized.
When the image data are preserved under the condition that the image data are not compressed, the image information is less lost, and images with high image quality can be provided when images are composed.
In the image processing method of the Second structure, an image on a silver halide film in which a date is photographed is converted into image data, the date is read, and the image data are subjected to image processing. Therefore, the image for which the date of photographing is old, for example, is considered to have color fading in accordance with the period for preservation, and the image is subjected to image processing corresponding to the extent of the color fading, thus the initial image quality can be reproduced.
It is further preferable that the image processing is a tone characteristic conversion processing corresponding to the date.
When the statistics of tone characteristics of the image are collected in accordance with the date stated above, and the tone characteristic conversion processing is conducted based on the statistics, the extent of color fading for the preservation period, for example, can be obtained statistically, which is preferable.
It is further preferable that the tone characteristic conversion processing is conducted based on at least one of histogram, cumulative histogram, the mean value, median, a mode, the standard deviation and dispersion, which are all image tone characteristics.
If the tone characteristic conversion processing is conducted for images stored in the same file, so that the tone characteristic may be constant, when the images are arranged in the order of photographing as in the case of an electronic album, for example, the tone is not changed extremely, and a feeling of physical disorder is not given to an observer.
In the image processing method of the Third structure, when image data are inputted from an electronic image recording apparatus, information about the date added to the image data is read, and the image data are subjected to image processing to be correlated with the date. With regard to the image for which the date of photographing is old, for example, therefore, it is possible to express natural color fading as in a photograph of a silver halide type, by conducting image processing so that sepia tone may be obtained corresponding to the time elapsed up to the present time.
If the image processing mentioned above is the tone characteristic conversion processing corresponding to the date stated above, image change corresponding to the time elapsed can be given, and it is possible to express a feeling which is more natural.
If the statistics of a change of tone characteristics of the image on a silver halide film corresponding to the time elapsed are collected and the tone characteristic conversion processing is conducted based on the statistics, it is possible to obtain statistically the extent of color fading of a silver halide photograph for the period, for example, during which the silver halide photograph has been preserved, which is preferable.
It is further preferable that the tone characteristic conversion processing is conducted based on at least one of histogram, cumulative histogram, the mean value, median, a mode, the standard deviation and dispersion, which are all image tone characteristics.
If the tone characteristic conversion processing is conducted for images stored in the same file, so that the tone characteristic may vary in accordance with the date of photographing, it is possible to obtain the image which seems as if it were faded in accordance with the time elapsed, resulting in an album that is close to one for silver halide photographs, which is preferable.